The first Norway's oil field- Ekofisk

Ekofisk, discovered in 1969, was the first commercial oil field discovered in Norway's North Sea sector. Then chief executive Egil Abrahamsen believed DNV's expertise could be applied to the emerging offshore sector, and wanted to position the company to seriously expand its activities beyond shipping. Offshore activities had few or no established rules, particularly in the harsh North Sea conditions. DNV's comprehensive technical expertise was therefore important for the successful development of Ekofisk. Several of its employees involved in the project recounted these pioneering times were a challenging and exciting period, with individuals given a great deal of responsibility and required to make quick decisions based on solid technological knowledge, experience and common sense.

Ekofisktank (Ekofisk T) consisted of several tanks surrounded by a breakwater. It had never before been undertaken so major developments such depths, and Phillips group had to solve many problems, not least in connection with unaccustomed wind and wave conditions. Norwegian industry undertook also major tasks, which earned Norway a solid foothold within the petroleum industry; Norwegian solutions, integrated platforms on concrete pillars, dominated for a time Norwegian shelf. It was eventually found a number of larger and smaller fields in the named Ekofisk area. These were linked to the Ekofisk Centre, which thus became more extensive and calculated to get a far longer lifespan than originally planned. The plants could conceivably be in production towards the middle of the 2000s.

Phase 1. In the period 1971-1974 were produced crude oil from four wells using subsea wellheads. As temporary production platform were used the jackup platform Gulftide. After treatment aboard the oil was passed through underwater cables to two anchored mooring and loading buoys and further onto tankers. The gas was burned. It was produced in all 3.8 million. Tons of oil (28 million. Barrels) in the period.

Phase 2. This phase included the development of major part of the Ekofisk Centre, where all platforms except Ekofisk T is framework constructions in steel. Ekofisk T is a combined platform and the storage tank in concrete. It consists of nine cylindrical concrete tanks resting on a base and is surrounded by a perforated breakwater wall. Upstairs mind is fitted with a steel deck which carries processing equipment. It is 92 meters in diameter 82 m tall and weighs 235,000 tons. Tanks take 135,000 tons (1 million. Barrels) of crude oil. Construction began in a dry dock in Jåttåvågen between Sandnes and Stavanger, and was completed in Hill harbor at Stavanger. The idea was later towed out to Ekofisk and sunk to the bottom (1973). Main constructor was the French firm Doris, with Norwegian Contractors as main contractor. Ekofisk T meant a breakthrough for concrete structures in offshore petroleum activities. Three drilling platforms, A (Alpha) , B (Bravo) and C (Charlie) , served as drilling platforms during drilling of production wells, and as platforms for the assembly of wellheads and other necessary equipment during the production phase. A is located far south of the Ekofisk Centre B a piece to the north. It was at B it happened a blow from one of the wells during overhaul in April 1977 (Bravo accident ). Several other platforms, including terminal platform FTP(Field Terminal Platform) , accommodation platform Q (Quarter Platform)and pump platform P was installed in this phase.

Phase 3. This phase included the laying of oil and gas pipelines respectively.Teesside (1975) and Emden (1977) (see Norpipe ) with pressure increase platforms and terminals (Emden terminal, Teesside terminal), and steel platforms Cod, Tor and West Ekofisk and pipelines from these to the Ekofisk Centre. Besides the construction of a receiver platform (R) and mounting accessories on Ekofisk T and pumping platform (P).

Phase 4 . Approval for the fourth expansion phase was given in 1975. This phase included the building of a residential platform, Ekofisk Hotel, at the Ekofisk Centre and the development of the Albuskjell Edda and Eldfisk.Albuskjell was developed with two steel platforms, Edda with one. Here overturned residential platform Alexander L. Kielland 27. March 1980 with the loss of 123 lives. Eldfisk was equipped with two drilling and production platforms as well as a terminal platform

Phase 5. This phase is a result of the desire to increase the recovery rate in the Ekofisk field. To maintain reservoir pressure so that one could increase the recovery rate, it was built one water platform. This became operational in 1987. The water injection capacity on the field is subsequently been repeatedly extended and is currently at over 800,000 barrels / day. Embla field was approved for development in 1990 and production started in 1993.

Ekofisk 2. In 1994 the Parliament approved the plans for development that ensures continued operation on Ekofisk. Production license and Norpipe transport permit was prolonged out 2028. A new Ekofisk Center with new drilling and production platform (Ekofisk 2/4 X) and a new platform for processing and transport (Ekofisk 2/4 J) was opened in autumn 1998. The latter platform has processing capacity of 41,600 m 3 of oil, 21.2 million. m 3of gas and 31 800 m 3 of water per day. A new production and processing platform (Ekofisk M) was installed in 2007. The new platforms are designed to withstand up to 20 meters subsidence, is intended for 30 years of operation and will replace all the old platforms. The development cost approximately 17bn. Kroner. Total will eventually 14 platforms on the Norwegian side and two platforms in the UK shut down.

Subsidence

In 1984 it was discovered that the seabed at the Ekofisk had subsided. It was due to the chalk reservoir rocks were compressed as gas and oil was recovered. During the actual Ekofisk subsidence was 3 m, at West Ekofisk 0.6 m. The other fields were not affected. To withstand centuries wave was therefore all steel platforms at the Ekofisk Centre raised (1987) with 6 m using 100 hydraulic jacks, each with a lifting capacity of 600 tons. Then, the mounted extension pieces on the total of 44 platform legs. Around Ekofisk T was installed a protection wall. Subsidence has continued and is now around 7 meters. The new platforms, which came into operation in 1998, is built to withstand up to 20 m subsidence. In 2003, the development project Ekofisk Growth approved. The project intends to increase recovery from Ekofisk 182 million. Boe. The development consists of a new platform, drilling of 25 wells, increased processing capacity and laying an electric cable for common power supply.

The name

The name Ekofisk is a construction; Phillips put English fish names promising structures (Anchovis, Sprat, Cod, Dace, Eel etc.), But ran out of names on E and created a "Norwegian" name: Ekofisk.

Ekofisk as heritage

Ekofisk has had status as technical-industrial monument from 2005. It means that everything about "offshore city" which has significance for the knowledge about oil and gas era in Norway, will be documented. The Norwegian Petroleum Museum in Stavanger has the professional responsibility for the project. It was originally NPD asked Phillips Petroleum Co. to initiate a pilot project for securing Ekofisk facilities that heritage, and the decision was taken by the establishment Cultural Heritage.